On May 8th, the RCDD published a paper in the journal ERJ Open, detailing an evaluation of FluoroType MTB (Hain Lifescience, Germany), a new molecular test for the detection of pulmonary tuberculosis. The evaluation took place at Zankli Research Laboratory in Abuja, Nigeria, which is a key collaborating site in the Diagnostics Evaluation Platform at the RCDD.
The study involved 296 patients with suspected tuberculosis, who were all tested by culture, LED smear microscopy, Xpert MTB-Rif, and the new test. FluoroType MTB was found to be a sensitive test, identifying 89% of culture positive cases, including 100% of those that were positive by microscopy. However, the specificity of the test (60%) was found to be lower than in previous evaluations in low burden countries.
This was the first evaluation of the test in a high burden country, and such settings can pose difficulties for the implementation of complex molecular tests. The manual DNA extraction used in the process was highlighted as being a potential point where cross contamination can lead to poor specificity. The producer of the test does manufacturer an automated extraction system, and it is anticipated the use of this could improve specificity in laboratories dealing with large sample volumes.
Obasanya, J., Lawson, L., Edwards, T., Olanrewaju, O., Madukaji1, L., Dacombe, R., Dominguez, J., Molina-Moya, B., Adams, E.R., Cuevas, L.E. (2017). FluoroType MTB system for the detection of pulmonary tuberculosis in Nigeria. ERJ Open.
See also: Abdurrahman ST, Lawson L, Blakiston M, et al. Are patients with pulmonary tuberculosis who are identified through active case finding in the community different than those identified in healthcare facilities? New Microbes and New Infections. 2017;15:35-39. doi:10.1016/j.nmni.2016.10.002.